Re: [baofeng_uv5r] Re: Low Input Power RF Amplifiers

Apr 6, 2013



#24946 Apr 6, 2013

Very interesting. The page you link certainly does exist, but doing a

search of the certification database for grantee code DJ7 and Product Code

418 produces the result "There are no applications on file that match the

search criteria specified: Grantee Code: DJ7 Product Code: 418" but doing a

search for JUST Grantee Code DJ7 finds the approvals for the 418 (along with

all other Ten-Tec approvals). Doing a search for Product Code 418 without

any Grantee Code also fails to find any results. Apparently there is a

problem with the FCC's own database search engine recognizing the 418

product code in the ID number.

According to Ten-Tech's "Test Report" information provided to the FCC "The

amplifier operates only in the amateur radio bands below 30 MHz and also in

the 6 meter amateur band (50-54 MHz). The amplifier is NOT capable of

operation on any frequency outside of the amateur bands including 26-28 MHz

and also will NOT operate above 54 MHz" and "The Ten-Tec Model 418 external

RF amplifier is not capable of amplification in the frequency band 26-28 MHz

and cannot be modified to operate in the 26-28 MHz frequency band. Any

attempt to drive the amplifier in the 26-28 MHz frequency band will result

in 0 dB gain from input to output of the amplifier." but their test

documentation shows no indication of any specific test performed to support

these statements.

Ten-Tec performed all Part 2 and Part 97 testing in house and describes the

test setup and procedures: "The setup to measure the RF power output was

made by connecting the output of a Ten-Tec Model 599 transceiver (the

exciter) to the input of the Ten-Tec Model 418 amplifier. A watt-meter was

placed in-line between the amplifier and a 50 ohm load. The exciter was

tuned to a frequency in the center of each band shown." Nothing in their

documentation indicates that they performed any testing at or beyond the

edges of any of the amateur bands or in the range 26-28 MHz to support their

statements. The exciter they used was their own model 599 which was probably

not modded for out of band operation.

I suspect you are right that the microprocessor controls to prevent

operation in the 26-28 MHz range could probably be defeated but I doubt many

people capable of doing that would be interested in using the Ten-Tec 418 as

an amplifier given its high price compared to readily available illegal amps

and legal amps that are easy to modify. It is hardly an amplifier that

would seem logical to be paired with a cheap Chinese HF transceiver.

-----Original Message-----

From: wb8grs

Sent: Saturday, April 06, 2013 00:25 AM


Subject: [baofeng_uv5r] Re: Chinese ssb/cw qrp rig

Here's a link to the FCC website regarding the Ten-Tec Model 418 amplifier

. Tons of information. The article in the February, 2013 QST magazine on

this amplifier says they use an internal frequency counter and

microprocessor to prevent the amplifier from operating between 26 to 28 MHz.

While I can understand how this is been done, I think it could be defeated

without much trouble, but then again, I'm just guessing. Read the article

if you have access to it.



--- In, "N4AOF" N4AOF@...> wrote:


> Interesting. Especially since none of the documentation indicates

> certification as required by 97.315.


> From: Ken Stone









> On Fri, Apr 5, 2013 at 10:41 AM, N4AOF N4AOF@...> wrote:



> Would you care to mention any specific model, low input power amplifiers

> that operate at 10 meters as sold by the factory?







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